Render Presentation with Fallback Font

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The following example includes these steps:

  1. We create fallback font rules collection.
  2. Remove() a fallback font rule and AddFallBackFonts() to another rule.
  3. Set rules collection to FontsManager::set_FontFallBackRulesCollection() property.
  4. With Presentation::Save() method we can save presentation in the same format, or save it in another one. After fallback font rules collection is set to FontsManager, these rules are applied during any operations over the presentation: save, render, convert, etc.
// Create new instance of a rules collection
auto rulesList = MakeObject<FontFallBackRulesCollection>();

// Create a number of rules
rulesList->Add(MakeObject<FontFallBackRule>(static_cast<uint32_t>(0x400), static_cast<uint32_t>(0x4FF), u"Times New Roman"));
//rulesList.Add(new FontFallBackRule(...));

for (const auto& fallBackRule : rulesList)
{
	// Trying to remove FallBack font "Tahoma" from loaded rules
	fallBackRule->Remove(u"Tahoma");

	// And to update of rules for specified range
	if ((fallBackRule->get_RangeEndIndex() >= static_cast<uint32_t>(0x4000)) && 
		(fallBackRule->get_RangeStartIndex() < static_cast<uint32_t>(0x5000)))
	{
		fallBackRule->AddFallBackFonts(u"Verdana");
	}
}

// Also we can remove any existing rules from list
if (rulesList->get_Count() > 0)
{
	rulesList->Remove(rulesList->idx_get(0));
}

auto pres = System::MakeObject<Presentation>(u"input.pptx");
// Assigning a prepared rules list for using
pres->get_FontsManager()->set_FontFallBackRulesCollection(rulesList);

// Rendering of thumbnail with using of initialized rules collection and saving to PNG
pres->get_Slides()->idx_get(0)->GetThumbnail(1.f, 1.f)->Save(u"Slide_0.png", ImageFormat::get_Png());
Create Fallback Fonts Collection